This fits well with the law stated in the Gemara that a decree that is not accepted by all Israel has not validity. Even is so even though at first it was thought that the decree was accepted, and then the courts went out and checked and saw that people did not in fact accept it.
The implication for us nowadays is that we ought to concentrate on keeping the laws of the Torah which are divine, and be aware that much of what people think are obligatory decrees from the later sages are no longer applicable since most of Israel do not abide by them. [That is the case even though the religious imagine that only they are Israel and everyone else is a goy.]
